While I do think quality of subs can be quite high (much higher than discourse here for certain topics and certain subs), this is a pretty well known problem. Discussion on this [1] from a post I made earlier.

r/sanfrancisco is quite negative on the current mayor Daniel Lurie and frequently expresses approval for Zohran Mamdani even though Lurie has an approval rate of 74% in SF [2] while Mamdani has a 69% favorability [3] in NYC largely because of the political skew of the sub.

[1]: https://news.ycombinator.com/item?id=49556546

[2]: https://www.sfchronicle.com/politics/article/sf-mayor-lurie-...

[3]: https://sri.siena.edu/2026/09/23/siena-poll-of-likely-new-yo...